Hi guys, is it feasible to get an ultrasonic rangefinder to track a person? I am working on an idea for a robot to follow me around. I have seen youtube videos of laser scanners being able to follow a person and follow them like a duck, but these scanners cost $2500. The sonar costs about $60, but I am not sure how they will act when it's following me in a crowd. I was also trying to figure out a way to use bluetooth as a way to track my position, but I don't know what that kind of device would be called or if it is even made. Will any of this work?